Hum from Grado on LP12.. Better carts to consider?


I've had a problem with hum on my LP12 for as long as I can remember. The table (bought used) came with a Grado Signature 8MZ and I've since tried a Grado Z+ that I had from another table. Both have the same amount of hum. I have a lot of RF and noisy AC in my house. The hum is noticeable when I switch to phono and gets louder as I move the cart over the rim of the platter. From there it decreases as I move the arm towards the spindle. (The table is 80's vintage with Ittok and Circus/Lingo upgrades).

A (non-Linn) dealer said 'oh Grados do that on LP12s - lack of shielding'. My Linn dealer didn't nave a strong opinion. He suggested a Benz Ace H given my under- $700 budget. From reading the Agon forums, some think an AT150 M series has better sound for less $. I've also heard good things about the Dynavector DV-20X. Does MM/MI vs. HOMC matter in terms of hum or is the degree of 'shielding' a variable from cartridge to cartridge no matter which type? Does a good review on a MC necessarily extend to the HO version, as opposed to the LO/MO versions?

My system: ARC PH1 (48 dB gain, variable loading via soldering iron)
ARC LS2BII
PSE Studio IV/V's
Audio Physic Tempo III's
FWIW: Meridian 508 CD player is dead quiet in this system.

Music: from Joni Mitchell to Ian Dury and the Blockheads, Monk to Mozart.

Thanks for any knowledge you can impart!
geor
Might look at a Lyra Dorian I think those are around 700.00I have a Troika on mine and it works well. There is a synergy with Linn. I saw a re-tipped Troika list here the other day. But I have heard the Lyra Skala and Helikon on LP12s and they work well too. I would eventually like to try a Helikon or if extra$$ show up a Skala. The Lyra hous sound is a very open, musical yet detailed sound that I like very much, you might investigate. Lyra had a trade up program that they may run again and in a year or so you could step up.
Agree with the AT150 for performance and no hum. Bang for the buck is off the charts.
Yes. I would second the suggestion of a Lyra cartridge for your LP12. The reason they are such a good match for the Linn table is that Lyra used to manufacture all of Linns higher end MC phono carts, including the Troika, if I'm not mistaken. I'm not sure if they still do.